This invention relates to chemical lasers of the visible type. More particularly, this invention concerns itself with an optically pumped, chemical gas lasing system which utilizes iodine monofluoride (IF) as a lasing medium
The recent development of devices and systems for generating and amplifying coherent electromagnetic energy in the optical frequency range, generally referred to as lasing action, has generated a great deal of interest in using these systems in a wide variety of industrial and military applications. A number of systems have evolved which are capable of generating a lasing action. These systems employ an optically active component, often referred to as a lasing or gain medium, from which the coherent electromagnetic energy is extracted by means of a phenomenon called population inversion. The optically active component possesses an unstable energy state capable of releasing photons as it decays to a lower energy state. The active component may be a liquid, solid or gas and the requisite population inversion can be accomplished by the direct generation or pumping of higher energy states through the mechanism of a chemical reaction, electron beam excitation, electron discharge excitation gas dynamics or optical radiation.
Flowing gas lasers, the subject matter which concerns this invention, generally achieve the pumping or generation of the lasing action through a chemical reaction between an energizing reactant, such as vibrationally excited nitrogen, and a lasing reactant, such as carbon dioxide. Other gaseous products such as nitrous oxide, helium, hydrogen, fluorine and mixtures thereof are known for their lasing action. These gas systems are generally preferred for high energy laser devices. In recent times however, a special interest has developed in systems for producing short wavelength chemical lasers for military applications since they would have distinct advantages over gas systems such as the HF/DF lasing devices. As a consequence, a considerable research effort has evolved in an attempt to provide a solution to the problem of providing a simple, efficient and dependable short wavelength frequency laser. Among the more interesting compounds or class of molecules considered during the research effort referred to above are the diatomic halogen compounds. There is a large amount of kinetic data available about these interhalogens which would indicate that some of them might make excellent candidates for electronic transition chemical laser systems of the visible type. As a result of the above research effort, it was found that a lasing action could be produced by optically pumping a lasing medium composed of iodine monofluoride. The ground state iodine monofluoride was produced by reacting iodine and fluorine which formed a flaming reaction product of iodine monofluoride. The iodine monofluoride was then optically pumped to the necessary energy levels by a pulsed dye laser. Several different laser lines from bright red (6634.ANG.) to near infrared (7208.ANG.) were produced.